Fuelcut on rebuild stock motor
 

Hi ohh knowledgeable forum :)

I have a rebuild 90´T2 - NO mods at all - running smooth as silk.
Problem is that i hit fuelcut whenever going WOT, though if i feather the throttle it will build up pressure and hold a steady 7psi all the way to the overrev buzzer.
Please help me out

I've checked:
Boost solenoid
Wastegate actuator
Replaced vacuumhoses
Checked for leaks
CAS

Thanks
- Kim

test the wastegate by applying 5-10psi of line pressure or use a mityvac and put it under a vacuum and see if the wastegate actuator is leaky/moving freely.

i have a few wastegate actuators that have ripped internal diaphragms so it is a possibility and the result will be an overboost condition.

also be sure the line from the compressor housing to actuator is in place and not ripped. the hard line port from the compressor to the hose can also wiggle loose as i have seen a few times as well.

those are the only real causes i can see with a stock system that shouldn't be creeping boost.

Heh, thats about the only two things i havent checked yet.
Just made sure the actuator moved when applying pressure, time to dig out the mityvac.

Thanks man :)

if you have a small tear in the diaphragm it may open but only with excessive pressure.

an easy way to test actuators off the vehicle is to push/pull on the actuator arm until it bottoms and then place your finger over the port and let pressure off the rod, if it holds for more than a few seconds you should be fine. this works if you don't have access to a mityvac.

Fixed.
Turned out to just be a torn vacuumhose for the wastegate.

Thanks guys